J'ai écrit un script qui affiche les différences entre deux commits, fonctionne bien sur Ubuntu.
https://gist.github.com/jacobabrahamb4/a60624d6274ece7a0bd2d141b53407bc
#!/usr/bin/env python
import sys, subprocess, os
TOOLS = ['bcompare', 'meld']
def execute(command):
    return subprocess.check_output(command)
def getTool():
    for tool in TOOLS:
        try:
            out = execute(['which', tool]).strip()
            if tool in out:
                return tool
        except subprocess.CalledProcessError:
            pass
    return None
def printUsageAndExit():
    print 'Usage: python bdiff.py <project> <commit_one> <commit_two>'
    print 'Example: python bdiff.py <project> 0 1'
    print 'Example: python bdiff.py <project> fhejk7fe d78ewg9we'
    print 'Example: python bdiff.py <project> 0 d78ewg9we'
    sys.exit(0)
def getCommitIds(name, first, second):
    commit1 = None
    commit2 = None
    try:
        first_index = int(first) - 1
        second_index = int(second) - 1
        if int(first) < 0 or int(second) < 0:
            print "Cannot handle negative values: "
            sys.exit(0)
        logs = execute(['git', '-C', name, 'log', '--oneline', '--reverse']).splitlines()
        if first_index >= 0:
            commit1 = logs[first_index].split(' ')[0]
        if second_index >= 0:
            commit2 = logs[second_index].split(' ')[0]
    except ValueError:
        if first is not '0':
            commit1 = first
        if second is not '0':
            commit2 = second
    return commit1, commit2
def validateCommitIds(name, commit1, commit2):
    if not commit1 and not commit2:
        print "Nothing to do, exit!"
        return False
    try:
        if commit1:
            execute(['git', '-C', name, 'cat-file', '-t', commit1])
        if commit2:
            execute(['git', '-C', name, 'cat-file', '-t', commit2])
    except subprocess.CalledProcessError:
        return False
    return True
def cleanup(commit1, commit2):
        execute(['rm', '-rf', '/tmp/'+(commit1 if commit1 else '0'), '/tmp/'+(commit2 if commit2 else '0')])
def checkoutCommit(name, commit):
    if commit:
        execute(['git', 'clone', name, '/tmp/'+commit])
        execute(['git', '-C', '/tmp/'+commit, 'checkout', commit])
    else:
        execute(['mkdir', '/tmp/0'])
def compare(tool, commit1, commit2):
        execute([tool, '/tmp/'+(commit1 if commit1 else '0'), '/tmp/'+(commit2 if commit2 else '0')])
if __name__=='__main__':
    tool = getTool()
    if not tool:
        print "No GUI diff tools, install bcompare or meld"
        sys.exit(0)
    if len(sys.argv) is not 4:
        printUsageAndExit()
    name, first, second = None, 0, 0
    try:
        name, first, second = sys.argv[1], sys.argv[2], sys.argv[3]
    except IndexError:
        printUsageAndExit()
    commit1, commit2 = getCommitIds(name, first, second)
    if validateCommitIds(name, commit1, commit2) is False:
        sys.exit(0)
    cleanup(commit1, commit2)
    try:
        checkoutCommit(name, commit1)
        checkoutCommit(name, commit2)
        compare(tool, commit1, commit2)
    except KeyboardInterrupt:
        pass
    finally:
        cleanup(commit1, commit2)
    sys.exit(0)